Generation an induced pluripotent stem cell line SXMUi001-A derived from a hemophilia B patient carries variant F9 c.223C＞T(p.R75X)

Exploiting urine-derived induced pluripotent stem cells for advancing precision medicine in cell therapy, disease modeling, and drug testing

The field of regenerative medicine has witnessed remarkable advancements with the emergence of induced pluripotent stem cells (iPSCs) derived from a variety of sources. Among these, urine-derived induced pluripotent stem cells (u-iPSCs) have garnered substantial attention due to their non-invasive and patient-friendly acquisition method. This review manuscript delves into the potential and application of u-iPSCs in advancing precision medicine, particularly in the realms of drug testing, disease modeling, and cell therapy. U-iPSCs are generated through the reprogramming of somatic cells found in urine samples, offering a unique and renewable source of patient-specific pluripotent cells. Their utility in drug testing has revolutionized the pharmaceutical industry by providing personalized platforms for drug screening, toxicity assessment, and efficacy evaluation. The availability of u-iPSCs with diverse genetic backgrounds facilitates the development of tailored therapeutic approaches, minimizing adverse effects and optimizing treatment outcomes. Furthermore, u-iPSCs have demonstrated remarkable efficacy in disease modeling, allowing researchers to recapitulate patient-specific pathologies in vitro. This not only enhances our understanding of disease mechanisms but also serves as a valuable tool for drug discovery and development. In addition, u-iPSC-based disease models offer a platform for studying rare and genetically complex diseases, often underserved by traditional research methods. The versatility of u-iPSCs extends to cell therapy applications, where they hold immense promise for regenerative medicine. Their potential to differentiate into various cell types, including neurons, cardiomyocytes, and hepatocytes, enables the development of patient-specific cell replacement therapies. This personalized approach can revolutionize the treatment of degenerative diseases, organ failure, and tissue damage by minimizing immune rejection and optimizing therapeutic outcomes. However, several challenges and considerations, such as standardization of reprogramming protocols, genomic stability, and scalability, must be addressed to fully exploit u-iPSCs' potential in precision medicine. In conclusion, this review underscores the transformative impact of u-iPSCs on advancing precision medicine and highlights the future prospects and challenges in harnessing this innovative technology for improved healthcare outcomes.

Gene Therapy Approaches for the Treatment of Hemophilia B

In contrast to the standard enzyme-replacement therapy, administered from once per 7-14 days to 2-3 times a week in patients with severe hemophilia B, as a result of a single injection, gene therapy can restore F9 gene expression and maintain it for a prolonged time. In clinical research, the approach of delivering a functional copy of a gene using adeno-associated viral (AAV) vectors is widely used. The scientific community is actively researching possible modifications to improve delivery efficiency and expression. In preclinical studies, the possibility of genome editing using CRISPR/Cas9 technology for the treatment of hemophilia B is also being actively studied.

Generation of an mESC model with a human hemophilia B nonsense mutation via CRISPR/Cas9 technology

BACKGROUND

Hemophilia B is a rare inherited genetic bleeding disorder caused by a deficiency or lack of coagulation factor IX, the gene for which (F9) is located on the X chromosome. Hemophilia B is currently incurable and the standard treatment is coagulation factor replacement therapy. Although gene therapy has the potential to cure hemophilia, significant barriers are still needed to be overcome, e.g., off-target effects and immunoreactivity, so new approaches must be explored. Nonsense mutations account for 8% of all the hemophilia B mutation types and can result in the development of coagulation factor inhibitors. In this study, CRISPR/Cas9 technology was used to construct a mouse embryonic stem cell model with a hemophilia B nonsense mutation (F9 c.223C > T) in humans to investigate the pathogenesis and treatment of nonsense mutations in hemophilia B.

METHODS

First, a donor plasmid with a mutation (F9 c.223 C > T) and sgRNAs were constructed. Second, both the donor plasmid and the px330-sgRNA were electroporated into mouse embryonic stem cell, and the mutant cells were then screened using puromycin and red fluorescence. Third, the mutant cell lines were tested for pluripotency and the ability to differentiate into three layers. Finally, the effect of mutation on gene function was studied in the differentiation system.

RESULTS

The mutant vector and effective sgRNA were constructed, and the mutant cell line was screened. This mutant cell line exhibited pluripotency and the ability to differentiate into three layers. This point mutation affects F9 expression at both the RNA and protein levels in the differentiation system.

CONCLUSIONS

The mutant cell line obtained in the current study had a single-base mutation rather than a base deletion or insertion in the exon, which is more similar to clinical cases. In addition, the mutant has the characteristics of mouse embryonic stem cells, and this point mutation affects F9 gene transcription and translation, which can be used as a disease model for studying the pathogenesis and treatment of hemophilia at the stem cell level.